C1 Heater hose diameters

[Larry P.]

The Hoses I got from CC are not gonna fit the fittings on my manifold or water pump. I got two different size hoses. I assume the smaller is the out, back to the manifold and the larger goes from the pump to the heater core. The fittings on my manifold are about 7/8 outside diameter. The smaller hose is 5/8 ID.
What size should the fittings be on the mainfold and water pump? Is this another case of incorrect "correct" hoses?
LP

[Mike E.]

Re: C1 Heater hose diameters

Larry--Corvettes are similar to Chevy passenger cars of the vintage--hoses are 5/8 and 3/4 ID. Sounds like incorrect fittings rather than incorrect hoses to me.

[Joe L.]

Re: C1 Heater hose diameters

Larry-----

The intake manifold fitting for ALL C1s (as well as C2 and C3) used a fitting with a nipple for 5/8" ID hose. However, C1 manifolds used a fitting with 3/8" NPT threads whereas later used 1/2" NPT. In any event, the nipples are all sized for 5/8" ID hose. So, I don't know what you have.

The waterpump heater hose fitting was different for different C1 years, though. For 1955-to ABOUT 1958, a fitting with 3/8" NPT and a nipple for 5/8" heater hose was used. Later C1 (ABOUT 1959-62) used a waterpump fitting with 1/2" NPT and a nipple for 3/4" ID hose. All later C2 and C3 also used this same size fitting, although several different configurations were used.

[Larry P.]

Thank you *NM*

[Debra P.]

Re: C1 Heater hose diameters

Hi Larry,
I just replaced the water pump & had my original radiator restored on my 58, the car is now text book. Corvette Central supplied the hoses. Like Mike said, it was most likely the fitting not the hoses. The same thing happened to me. While your at it, you may want to get your belt from Quanta, they are in the Driveline. Nice folks to deal with.
Cheers,
Deb
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